Dementia affects 4 to 5 million older adults in the United States. Dementia is a disease that affects the memory and the cognitive skills, as well as the ability to perform everyday activities.

A new study reported a decline in the prevalence of dementia in the United States between 2000 and 2012. Researchers from the University of Michigan studied more than 21,000 adults over the age of 65, using data from the Health and Retirement study from 2000 and 2012. The overall prevalence of dementia decreased from 11.6% in 2000 to 8.8% in 2012. The authors believe that the decline is primarily due to two factors.

"Dementia is characterized by declines in memory and other cognitive functions, like speech, and inability to plan and organize one's day", says Dr. Kenneth Langa, a professor at the University of Michigan, who focuses on research on epidemiology with an emphasis on Alzheimer’s disease and other dementias.

Langa attributes the decline in dementia prevalence to two factors:

Increases in the level of education

Improvements in treatment for diabetes, obesity, and hypertension

This suggests that a 75-year-old today has a lower risk of having dementia than a 75-year-old 10 or 20 years ago. Both increases in education and better control of cardiovascular risk factors may be important and explaining some of this decline. However, he emphasizes that more work needs to be done both in the U.S. and abroad to keep dementia trends on the decline.